Fire-alarm.



an. MERRELL.

, FIRE ALARM. 128441 1.

APPUACATION FILED mm. 20. m7.

Patented Nov. 12,1918.

I 5440mm REM efdall UNITED STATES PATENT OFFICE.

FREDERICK IR. MERBELL, 0F DALLAS, TEXAS, ASSIGNOR T0 FRED M. ROBINSON, OF

. WEST HAVEN, CONNECTICUT.

FIRE-ALARM.

Specification of Letters Patent.

Patented Nov. 12, 1918.

To all whom it may concern:

Be it known that I, FREDERICK R. MER- BELL, a citizen of the United States, residing at Dallas, in the county of Dallas and State of Texas, have invented certain new and useful Improvements in Fire-Alarms, of which the following is a specification.

My invention relates to new and useful improvements in fire alarms, the primary object of my invention being the provision of an alarm device adapted, when the temperature in a building or other structure reaches a predetermined height, to close a signal circuit.

One of the primary objects of my invention resides in constructing a circuit closer in which a spring constantly urges a contact toward a fixed contact, such movement of the first contact being normally prevented by a support of metal which will fuse at a relatively low temperature.

Another object which I have in view is the provision of a neat and Ornamental housing for the circuit closer.

With these and other objects in view, my invention will be more fully described, illustrated in the accompanying drawings, then specifically pointed out in the claims which are attached to and form a part of this application.

In the drawings:

Figure 1 is a perspective view of my fire alarm;

Fig. 2 is a vertical central sectional view;

Fig. 3 is a perspective view of the circuit closer removed from the casing.

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawings by the same reference characters.

My fire alarm device includes a substantially semispherical casing 10 of sheet metal or other suitable material provided with a laterally directed peripheral flange 11 to seat the edge of a disk-shaped base or cover plate 12, screws 13 or other fastening means being passed through alined openings formed in the flange and base plate and into any suitable support, such as the ceiling 14 of a room. The flange 11 at diametrically opposite points is bent to provide seats 11 for the end portions of a bracket, indicated as a whole by the numeral 15 and certain of the screws pass through the ends of this bracket so that the screws serve to hold the two casing sections and bracket together and to secure the entire device to a suitable support.

The bracket 15 is preferably formed from a single strip of metal of suitable character which is bent or doubled upon itself to provide an car 16 to be clamped between the flange 11 and cover plate and which has its ends brought together to provide a second car 17 for similar engagement, one portion of the strip resting flatly against the inner face of the cover plate and the other being bowed downwardly to form a supporting yoke 18 substantially conforming to the curvature of the casing 10 except at one side where it is ofi'set inwardly, as shown at 19, and at its base where it is upstruck somewhat. as shown at 20. The upstruck portion 20, at either side, is formed with upwardly bent pivot ears 21 to receive a pivot pin 22 which is passed through the downbent ears at the sides of a movable contact strip 2d having one end upbent, as shown at 25, to provide a contact edge. The inwardly offset portion 19 of the bracket is formed with an opening to receive a bushing 26 of insulating material having a flange engaging against the outer face of the strip and a bolt 27 is passed through this bushing with its head engaging against theflange, through a strip of insulating material 28, and through a fixed contact plate 29 having one terminal bent outwardly, as shown at 30, for engagement by the terminal 25 of the plate 24:. A nut 31 serves to secure these parts together and also to secure one end of a conductor wire 32 forming a part of an alarm circuit. This conductor wire 32 leads through alined openings formed in the bracket and base plate 12 and another conductor wire 33 similarly led into the casing connects with the contact strip 24; so that when the contacts 2 1 and 29 engage each other a circuit may be closed through a suitable source of energy and a suitable electrically operated alarm device. such as a bell, gong or horn.

That end of the contact strip 2 1 remote from its active terminal 25 has an 'upbent centering ear 3% which seats one end of a helical expending spring 35, the opposite end of which is seated by a downstruck ear 36 stamped out of the bracket. Obviously, this spring tends to at all times hold the contact 24 in engagement with the contact 29.

The casing 10 is formed with a circular opening 37 substantially in alinement with the central portion of the contact 24 and a relatively thin plate 38, of some metal or alloy which will fuse at a relatively low temperature, is mounted in the casing to cover this opening, seating in the space provided by the upstruck part 20 of the bracket. A supporting stud or pin 39 has its head seated upon this plate 38 and its shank extended through an opening 4-0 in the bracket to engage the lower face of the contact 24 and normally hold such contact out of engagement with the contact 29.

The above described fire alarm or circuit closer may be mounted at any convenient point, such as upon the ceiling of a room and, if desired, a tubular conduit il may be provided for the passage of the conductor wires 32 and 33. From a reference to Fig. 2, which shows the normal condition of the device, its operation will be readily understood. In case of fire, the fusible plate 38 will melt and release the supporting stud 39 so that the spring 35 will swing the contact plate 24 into engagement with the contact plate 29 to release the alarm circuit. A number of fusible plates 38 may be provided with each circuit closer so that they may be readily replaced after operation of the de vice.

Although I have illustrated and described my invention in all its details of construction, it will of course be understood that I reserve the right to make any changes, within the scope of the appended claims, with out in the slightest degree departing from the spirit of my invention.

.Having thus described the invention, what is claimed as new is:

1. In a fire alarm, a housing, a bracket mounted within the housing, a fixed contact secured to the bracket but insulated there from, a swinging contact carried by the bracket, means coacting between the swinging contact and bracket normally tending to force the swinging contact into engagement with the fixed contact, the housing being formed with an opening, a plate of fusible material closing the opening, and means guided by the bracket engaging between the plate and swinging contact to normally hold the latter out of engagement with the fixed contact.

2. In a fire alarm, a housing, a bracket disposed within the housing and formed from a strip bent to provide a straight portion, and a yoke extending from the straight portion and supported thereby, a fixed contact carried by the yoke, a swinging contact pivoted upon the yoke, yieldable means bearing between the straight portion of the strip and the swinging contact and constantly tending to bring the contacts together, a fusible element, and means disposed between the fusible element and the swinging contact for holding the swinging contact away from the fixed contact.

3. In a fire alarm, a substantially semi spherical housing open at its upper end and provided with an axial opening therethrough, a closure plate for the upper end of the housing, a fusible plate overlying said opening in the housing and cooperating with said first mentioned plate to close the housing, a bracket arranged within the housing and including a yoke seating fiat against the wall of the housing and extending over said plate, a fixed contact carried by the said yoke, a swinging contact constantly urged to engage the fixed contact, and means resting upon the fusible plate and engaging the swinging contact for holding the said swinging contact away from the fixed contact.

In testimony whereof I affix my signature.

FREDERICK a. MERRELL. [1,. s.]

Copies of this patent may be obtained for five cents each, by addressing the Commissioner 0! Pstents, Washington, D. C. 

